If you have been reading about heptapeptide and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-04-07. Where a claim depends on a specific study, the study is described rather than over-claimed.
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Modeled on tuftsin |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues |
| Approximate molecular mass | Around 750 Da | Depends on counter-ion and hydration |
| Common forms | Lyophilized powder | Also described as aqueous solution |
| Primary origin of research | Russian laboratories | Mid-1990s onward |
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, with mass spectrometry used to confirm molecular mass and sequence information. Amino acid analysis and peptide mapping may supplement these methods. Certified reference standards are scarce, and many commercial lots are sold as research chemicals without a pharmacopoeial monograph. Regulatory treatment differs by country: Selank is a registered prescription medicine in Russia, while in the European Union and the United States it is not an approved drug and may fall under research-chemical or unapproved-product frameworks.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
== Pharmacology == Taxifolin is not mutagenic and less toxic than the related compound quercetin. It acts as a potential chemopreventive agent by regulating genes via an ARE-dependent mechanism. Taxifolin has shown to inhibit the ovarian cancer cell growth in a dose-dependent manner. However, in this same study, taxifolin was the least effective flavonoid in the inhibition of VEGF expression. There is also a strong correlation (with a correlation coefficient of 0.93) between the antiproliferative effects of taxifolin derivatives on murine skin fibroblasts and human breast cancer cells. Taxifolin has shown to have anti-proliferative effects on many types of cancer cells by inhibiting cancer cell lipogenesis. By inhibiting the fatty acid synthase in cancer cells, taxifolin is able to prevent the growth and spread of cancer cells. Taxifolin also stops the effects of overexpression of P-glycoprotein, which prevents the development of chemoresistance. Taxifolin does this via inhibition of rhodamine 123 and doxorubicin. The capacity of taxifolin to stimulate fibril formation and promote stabilization of fibrillar forms of collagen can be used in medicine. Also taxifolin inhibited the cellular melanogenesis as effectively as arbutin, one of the most widely used hypopigmenting agents in cosmetics. Taxifolin also enhances the efficacy of conventional antibiotics such as levofloxacin and ceftazidime in vitro, which have potential for combinatory therapy of patients infected with methicillin-resistant Staphylococcus aureus (MRSA).
immune response; wound healing; muscle strength (including respiratory muscles); renal capacity and depletion leading to water and electrolyte disturbances; thermoregulation; and menstruation. Malnutrition can lead to vitamin and other deficiencies and to inactivity, which in turn may pre-dispose to other problems, such as pressure sores. Unintentional weight loss can be the characteristic leading to diagnosis of diseases such as cancer and type 1 diabetes. In the UK, up to 5% of the general population is underweight, but more than 10% of those with lung or gastrointestinal diseases and who have recently had surgery. According to data in the UK using the Malnutrition Universal Screening Tool ('MUST'), which incorporates unintentional weight loss, more than 10% of the population over the age of 65 is at risk of malnutrition. A high proportion (10–60%) of hospital patients are also at risk, along with a similar proportion in care homes.
==== Effects in preclinical studies ==== Trazodone shows antidepressant- and anxiolytic-like effects in animals. However, it shows differences from certain other antidepressants, like the tricyclic antidepressants, in animals. For example, it does not reverse the behavioral effects of the monoamine depleting agent reserpine and does not potentiate the effects of amphetamine or levodopa. Similarly to antipsychotics, trazodone reduces spontaneous motor activity, spontaneous and elicited aggressive behavior, and exploratory behavior, among other effects. In addition, trazodone diminishes amphetamine-induced locomotor hyperactivity, although it does not inhibit apomorphine- or amphetamine-induced stereotypy. On the other hand, unlike antipsychotics, trazodone does not produce catalepsy, although it can do so at sufficiently high doses. Activation of the serotonin 5-HT2A receptor enhances striatal dopaminergic neurotransmission, while stimulation of the serotonin 5-HT2C receptor inhibits striatal dopaminergic neurotransmission. Trazodone is both a serotonin 5-HT2A and 5-HT2C receptor antagonist, but has about 15-fold greater potency as an antagonist of the 5-HT2A receptor relative to the 5-HT2C receptor. In addition, at higher doses, trazodone acts as a dopamine D2 receptor antagonist in animals. As a result of the preceding actions, trazodone may inhibit striatal dopaminergic neurotransmission. This may underlie exacerbation of parkinsonism seen in marmosets and in human case reports.
He was initiated into the Tau chapter of Alpha Chi Sigma at Cornell in 1949. At Cornell he elaborated and refined his Baker Lectures into his magnum opus, Principles of Polymer Chemistry which was published in 1953 by Cornell University Press. This quickly became a standard text for all workers in the field of polymers, and is still widely used to this day. Flory introduced the concept of excluded volume, coined by Werner Kuhn in 1934, to polymers. Excluded volume refers to the idea that one part of a long chain molecule can not occupy space that is already occupied by another part of the same molecule. Excluded volume causes the ends of a polymer chain in a solution to be further apart (on average) than they would be were there no excluded volume. The recognition that excluded volume was an important factor in analyzing long-chain molecules in solutions provided an important conceptual breakthrough, and led to the explanation of several puzzling experimental results of the day. It also led to the concept of the theta point, the set of conditions at which an experiment can be conducted that causes the excluded volume effect to be neutralized. At the theta point, the chain reverts to ideal chain characteristics – the long-range interactions arising from excluded volume are eliminated, allowing the experimenter to more easily measure short-range features such as structural geometry, bond rotation potentials, and steric interactions between near-neighboring groups.
Sources: en.wikipedia.org
=== Pharmacodynamics === In gout, probenecid competitively inhibits the reabsorption of uric acid through the organic anion transporter (OAT) at the proximal tubules. This leads to preferential reabsorption of probenecid back into plasma and excretion of uric acid in urine, thus reducing blood uric acid levels and reducing its deposition in various tissues. Probenecid also inhibits pannexin 1. Pannexin 1 is involved in the activation of inflammasomes and subsequent release of interleukin-1β causing inflammation. Inhibition of pannexin 1 thus reduces inflammation, which is the core pathology of gout.
==== Mexico ==== Two types of cider (sidra) are sold in Mexico. One type is a popular apple-flavoured, carbonated soft drink, sold under a number of soft drink brands, such as Sidral Mundet and Manzana Lift (both Coca-Cola FEMSA brands), Manzanita Sol (owned by PepsiCo), and Sidral Aga from Group AGA. The other type, alcoholic sidra, is a sparkling cider typically sold in Champagne-style bottles with an alcohol content comparable to beer. Sidra was, due to the expense of imported champagne, sometimes used as a substitute for New Year's Eve toasts in Mexico, as it is also a sweet, fruity drink. However, now the practice is to drink cider on Christmas Eve, celebrated with the family, and champagne on New Year's celebrated with friends. Cider beverages form a very small share of the Mexican alcoholic beverage market, with the figures for 2009 volume sales amounting to only 3.8 million litres.
GABAA in which the receptor is part of a ligand-gated ion channel complex GABAB metabotropic receptors, which are G protein-coupled receptors that open or close ion channels via intermediaries (G proteins)
Butyl lithium (n-C4H9Li) Lithium diisopropylamide (LDA) [(CH3)2CH]2NLi Lithium diethylamide (LDEA) (C2H5)2NLi Sodium amide (NaNH2) Sodium hydride (NaH) Lithium bis(trimethylsilyl)amide [(CH3)3Si]2NLi The strongest superbases are synthesised in only gas phase:
Andress, Jason. Winterfeld, Steve. (2011). Cyber Warfare: Techniques, Tactics and Tools for Security Practitioners. Syngress. ISBN 1-59749-637-5 Bodmer, Kilger, Carpenter, & Jones (2012). Reverse Deception: Organized Cyber Threat Counter-Exploitation. New York: McGraw-Hill Osborne Media. ISBN 0-07-177249-9, "ISBN 978-0-07-177249-5" Brenner, S. (2009). Cyber Threats: The Emerging Fault Lines of the Nation State. Oxford University Press. ISBN 0-19-538501-2 Carr, Jeffrey. (2010). Inside Cyber Warfare: Mapping the Cyber Underworld. O'Reilly. ISBN 978-0-596-80215-8 Conti, Gregory. Raymond, David. (2017). On Cyber: Towards an Operational Art for Cyber Conflict. Kopidion Press. ISBN 978-0-692-91156-3 Cordesman, Anthony H.; Cordesman, Justin G. (2002). Cyber-threats, Information Warfare, and Critical Infrastructure Protection: Defending the U.S. Homeland. Greenwood Publishing Group. ISBN 978-0-275-97423-7. Costigan, Sean S.; Perry, Jake (2012). Cyberspaces and global affairs. Farnham, Surrey: Ashgate. ISBN 978-1-4094-2754-4. Fritsch, Lothar & Fischer-Hübner, Simone (2019). Implications of Privacy & Security Research for the Upcoming Battlefield of Things. Journal of Information Warfare, 17(4), 72–87. Gaycken, Sandro. (2012). Cyberwar – Das Wettrüsten hat längst begonnen. Goldmann/Randomhouse. ISBN 978-3-442-15710-5 Geers, Kenneth. (2011). Strategic Cyber Security. NATO Cyber Centre.
Sources: en.wikipedia.org
Selank is a synthetic peptide made of seven amino acids. It is modeled on tuftsin, a natural tetrapeptide, with an added three-residue tail. It is not a small-molecule drug.
It originates from research in Russia, associated with the Institute of Molecular Genetics of the Russian Academy of Sciences. The first descriptions date to the mid-1990s. Most published studies come from Russian laboratories.
No, Selank itself does not occur naturally. Its backbone is based on tuftsin, which is produced in the body, but the seven-residue version is a synthetic construct. It is supplied as a manufactured peptide.
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.